1. Field
Example embodiments of inventive concept relate to memory systems and/or methods of controlling operations thereof, and more particularly, to integrated circuits and/or methods for dynamic frequency scaling.
2. Description of Conventional Art
A synchronous memory system, such as synchronous DRAM (SDRAM), operates in synchronization with a clock signal applied from the outside, or operates an internal circuit at a timing of a predetermined phase relationship with respect to a phase of a clock signal. In the synchronous memory system, a delay locked loop (DLL) circuit is required to remove the influence of a propagation delay of a clock signal. Therefore, a synchronous memory system using such a DLL circuit requires a technique to change the operating frequency of a clock signal quickly and reliably.